ch. 23 physiologic behavior and adaptation of the newborn at birth

Question 1

neonatal period: newborn physiologic adjustment tasks involve

Answer 1

birth to 28 days

1) newborn physiologic adjustment tasks involve
- establishing and maintaining respirations
- adjusting to circulatory changes
(a) closure of patent ductus arteriosis
(b) closure of foramen ovale
(c) closure of ductus venosis
(d) decrease in pulmonary resistance, increase vascular resistance
- regulating temperature
- ingesting, retaining, and digesting nutrients (human milk/formula)
- eliminating waste
- regulating weight (lose up to 10% body weight) -> will return in 2 weeks

Question 2

neonatal period: newborn behavior tasks include

Answer 2

• establishing a regulated behavioral tempo independent of the mother, which involves self regulating arousal, self monitoring changes in state, and patterning sleep
• processing, storing, and organizing multiple stimuli
• establishing a relationship with caregivers and the environment

Question 3

stages of transition to extrauterine life

Answer 3

1) major adaptations associated with transition from intrauterine to extrauterine life occur during the first 6-8 hours after birth

2) first period of reactivity:
- lasts up to 30 minutes after birth
- newborn’s heart rate increases to 160-180 bpm but gradually decreases after 30 minutes

3) periods of decrease responsiveness
- lasts from 60-100 minutes
- after first period reactivity, newborn either sleeps or has a marked decrease in motor activity
- pain, sleep/wake stress

Question 4

stages of transition to extrauterine life

Answer 4

• occurs 2-8 hours after birth
• lasts from 10 minutes to several hours
• tachycardia, tachypnea occur
• increased muscle tone
• improved skin color
• mucous production
• meconium typically passed

Question 5

physiologic adaptation: respiratory

Answer 5

1) initiation of breathing
- chemical factors: activation of chemoreceptors in carotid arteries/aorta
- mechanical factors: changes in intrathoracic pressure (decreased pulmonary pressure as newborn takes in air)
- thermal factors: stimulation of skin + respiratory center in the medulla (site for respiration in brain)
- sensory factors: suctioning, drying, lights, sounds, smell

2) establishing respiration

3) signs of respiratory distress:
- nasal flaring
- intercostal or subcostal (subclavicular, substernal) retractions
- grunting (no strong cry, trying to cry out but can’t, piggy sounds)

4) acrocyanosis:
- normal finding in the first 24 hours after birth
- blue hands/feet

Question 6

fetal respiratory system

Answer 6

1) fetal lung development
(a) 20-24 weeks
- alveolar ducts appear
(b) 24-28 weeks
- primitive alveoli
- alveoli epithelial cells differentiate into type 1 (structures necessary for gas exchange) and type II (structures that provide for synthesis & storage of surfactant) -> 8 months
- between 24-28 weeks, the # of type II cells increases

2) surfactant:
- surface active phospholipids critical for alveolar expansion, stability
- production peaks at 35 weeks (adequate)

3) intermittent detal breathing movements develop chest wall muscles
- diaphragm
- betamethasone, dexmethasone, ambubag, suction, CPAP/vent, fetus breathes in utero

Question 7

ability to maintain respiratory function

Answer 7

1) lung compliance
(a) influenced by:
- elastic recoil of lung tissue
- anatomic differences in newborn
- large heart and abdomen
- high diaphragm

2) airway resistance
- depends on radius length and number of airways

Question 8

cardiopulmonary adaptation

Answer 8

1) neonate’s first breaths initiate sequence of events
- airways emptied of fluid
- volume, function established
- fetal circulation converts to neonatal

Question 9

characteristics of newborn respiration